Electrophotoreceptor using styrene-maleic anhydride copolymer as the polymeric binder

Abstract

An electrophotoreceptor comprising a conductive substrate, a charge generation layer and a charge transport layer wherein the charge transport layer comprises a polymeric binder and a charge transport material. The improvement resides in that a copolymer of styrene and maleic acid is used as the binder in the charge transport material. The photoreceptor exhibits improved sensitivity, residual potential, durability and reproducibility.

I claim: 
     
       1. An electrophotoreceptor comprising: an electrically conductive substrate;   a charge generation layer, coated on said electrically conductive substrate, comprising a charge generation material selected from the group consisting of phthalocyanine pigment, bisazo pigment and squaraine pigment; and   a charge transport layer, coated over said charge generation layer, comprising a polymeric binder and a charge transport material, said polymeric binder being a copolymer of styrene and maleic anhydride, said copolymer characterized by a weight average molecular weight of from 100,000 to 300,000 and a styrene to maleic anhydride weight ratio in the range of between 99:1 and 80:20, and said charge transport material selected from the group consisting of hydrazone and pyrazoline.   
     
     
       2. The electrophotoreceptor according to claim 1, wherein said charge generation material is selected from the group consisting of phthalocyanine pigment and squaraine pigment. 
     
     
       3. The electrophotoreceptor according to claim 1, wherein said charge transport material is selected from the group of consisting of the compounds represented by the following formulae: ##STR9##